unit Unit6;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, jpeg, ExtCtrls;

type
  TForm6 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Button1: TButton;
    Edit4: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form6: TForm6;

implementation

{$R *.dfm}

procedure TForm6.Button1Click(Sender: TObject);

var a,b,h:integer;
s:real;
begin
a:=strtoint(edit1.text);
b:=strtoint(edit2.text);
h:=strtoint(edit3.text);
s:=(a+b)*h/2;
edit4.text:=floattostr(s);
end;

end.
 